This invention relates to a braiding device for application particularly in coil winding machines.
When a coil or spool of very thin metal wire is made, it is advisable to construct a braid at the ends of the winding, or to fit one thereto, in order to reinforce said ends and make them resistant to handling, for example when welding the ends to terminals, when taping the coil, when packing or the like.
In the oldest method, braids were constructed separately from the coil winding and then soft-soldered to the coil ends. In such a case it could happen that the solder flux contained traces of chlorides, which were able sooner or later to lead to a discontinuity in the winding. It was also necessary to isolate the soldered joint and braid from the winding with adhesive tape, the adhesive of which had to have absolutely non-corrosive properties.
For this reason, braiding devices have been used for some time for forming braids intermittently from the same single wire which forms the winding. These braids are always formed from an odd number of single wires, which are grouped parallel to each other by the combined action of hooks which are moved with reciprocating motion, or which are connected to endless chains. When the single wires have been formed into a parallel group, an additional element operates by rotation to twist the group.
In those machines, and in particular in turret coil winding machines, in which the winding wire is fed practically continuously, it is necessary for these braiding devices to be very fast. This is because as they have to obviously operate with the wire at rest (i.e. with the winding head not drawing wire), the braiding time is added to the winding time, so reducing the productivity of the machine.